Insects are of various types and shapes and are the largest group of animals on the earth. Their traces can be found in almost every corner of the world.

Until the beginning of the 21st century, there were more than 1 million species of insects known to humans, but there are still many species that have yet to be discovered. Insects are the largest group of arthropods. The most common ones are locusts, butterflies, bees, dragonflies, flies, grasshoppers, cockroaches, etc.

Not only are there many types of insects, but the number of individuals of the same species is also amazing. The distribution of insects is so wide that no other class of animals can compare with it, almost all over the earth. There are different types.

Most insects can be used as plant specimens and precious medicinal materials, which are good resources that humans can use.

Species classification

Coleoptera

Coleoptera is the largest order in the class Insecta, commonly known as "beetles". There are more than 330,000 species, accounting for 40% of the total number of insects. More than 7,000 species have been recorded in China. Their forewings are horny, hard, and veinless, and are called "elytra," hence their name. The exoskeleton is developed and the body is rigid, so it can protect the internal organs. The body shape changes greatly. These insects are highly adaptable. It has chewing mouthparts and has a wide range of feeding habits: it is divided into herbivorous - various leaf beetles and beetles; carnivorous - carabid and tiger beetles; detritivorous - beetles; cadaverous - burial beetles; coprophagous - Dung beetle.

This group belongs to complete metamorphosis, and the larvae have various forms due to different living environments and feeding habits; most of the pupae are naked pupae, and rare ones are covered pupae.

Lepidoptera

Lepidoptera is the second largest order in the class Insecta after Coleoptera. It is named because of the large number of scales on its body and wings. Mainly divided into moths and butterflies, the most common identifying feature is the siphon-type mouthparts, which are formed by the specialization of the outer jaw lobe of the lower jaw, and the upper jaw degenerates or disappears; complete metamorphosis; the body and wings are densely covered with scales and hairs; two pairs of wings , membranous, each with a closed middle chamber, and the wings are covered with scales, forming special markings, which are often used in classification; a few wingless or short-winged types; 6-segmented tarsi; no tail whiskers; holometamorphosis. The larvae are multi-legged. In addition to three pairs of thoracic legs, there are usually one pair of abdominal legs on the 3rd to 6th and 10th abdominal segments, but there are cases of reduction and specialization. There are toe hooks at the ends of the abdominal legs; stripes on the body of the larvae Important in classification; pupae are pupae. Adults generally feed on nectar, water and other substances and do no harm (except for a few, such as fruit-sucking exigua moths, which damage nearly mature fruits). Most of the larvae are terrestrial, herbivorous, and harm various plants; a few are aquatic.

Diptera

Diptera includes mosquitoes, grasshoppers, gnats, flies, flies, etc., and is a larger order in the class Insecta. It is named because the adult forewings are membranous and the hind wings degenerate into "balance sticks". Diptera is divided into three suborders: long-horned, short-horned and ring-lobed. The tentacles of the suborder Longhorns are more than 6 segments, including mosquitoes, grasshoppers, and gnats, and are a relatively low-level group; the tentacles of the suborder Brachycera are less than 5 segments, usually 3 segments, and are commonly known as "horse flies"; the suborder cyclops is what we commonly call them. of "flies".

Hymenoptera

Hymenoptera includes various ants and wasps. Hymenoptera insects have obvious characteristics, including chewing and sucking mouthparts, and the connection between the front and rear wings is completed by wing hooks. This group is widely distributed, with more than 100,000 known species and an estimated at least 250,000 species. According to whether the base of the abdomen is constricted and thinned, it is divided into broad-waisted suborder and thin-waisted suborder. The Eurylumid suborder is a lower herbivorous group, including sawflies, tree wasps, stem wasps and other groups; the Slenderid suborder includes most species of the Hymenoptera, including ants, wasps and various parasitic wasps.

Hemiptera

Hemiptera is composed of two suborders: Heteroptera and Homoptera. There are 133 families and more than 60,000 species. The suborder Heteroptera is the stink bug. It is one of the main groups in the class Insecta. The forewings of Hemiptera insects cover the back of the body when at rest, and the hind wings are hidden underneath. It is named because the base of the forewing of some taxa is ossified and thickened, becoming "semi-elytra-shaped". They have piercing and sucking mouthparts and feed on the juices from plants or other animals. It is an insect with incomplete metamorphosis. There are odor glands on its abdomen, which will emit volatile odorous liquid when encountering predators. The suborder Homoptera includes cicadas, aphids, etc. The classification of Hemiptera is still controversial. Homoptera was originally regarded as an independent order, and Hemiptera and Homoptera are still regarded as different orders in many places.

Orthoptera

Orthoptera is a relatively common group of insects, including katydids, crickets, mole crickets, locusts, etc. There are more than 20,000 species known in the world and they are widely distributed. . The forewings of adults are slightly hardened, called "covered wings", and the hind wings are membranous. This group undergoes incomplete metamorphosis, with nymphs and adults mostly feeding on plants, causing harm to agriculture, forestry, and economic crops; a few species are omnivorous or carnivorous. Orthoptera is a relatively primitive insect group, originating from the original Orthoptera. In the Upper Carboniferous Period, it has been divided into katydids with longer tentacles and locusts with shorter tentacles. Many of these species have become traditional ornamental insects due to their chirping or fighting habits, such as fighting crickets and katydids.

Euryoptera

Euryoptera is a smaller group, consisting of only two families: Mudflyidae and Odontidae. Distributed worldwide, about 300 species have been recorded. There are more than 40 known species in China, and common species include Palearctic mudflies, Oriental megalodon, Sinensis, etc. Some scholars classify it as a suborder of Neuroptera.

The adults of Euryptera are medium to large, with a body length of 8 to 65 mm and a wingspan of 24 to 175 mm. The front and rear wings are similar, the wing veins are mesh-like, and the wings are placed on the back in a roof-like shape. The veins at the front edge are not bifurcated; The wing hip area is broad and can be folded; there are many wing veins, but they are no longer divided into small forks at the outer edge, which can be distinguished from Neuroptera; the transverse veins on the front edge are in rows, simple or end-forked.

Odonata

The order Odonata is a relatively primitive group in the class Insecta, and it is also a smaller order. The order Odonata is divided into three suborders: the suborder Asteroptera, collectively known as "dragonflies"; the suborder Homoptera, collectively known as "turtles"; and two species of Mesoptera found in Japan and India. There are about 5,000 species in the world and more than 300 species in China. Dragonflies have a stout body, and their wings are spread flat on both sides of the body when resting; frogs have a slender body, and their wings are bunched on their backs when resting. Mesoptera have stout bodies and wings strapped to their backs. Odonata are insects with incomplete metamorphosis, and the larvae "water flies" live a predatory life in the water. The adults are also carnivorous species, preying on small insects, flying quickly and with a ferocious temperament.

Other insects

In addition to the above-mentioned 7 orders, there are 27 other orders in Insecta, totaling 34 orders. There are many types of insects with different shapes, but their common features are exoskeleton and three pairs of legs. Many of these species are familiar to us: the ephemeral order Ephemeroptera - the mayflies; the ferocious order Mantis - the praying mantis; the ubiquitous order Blattata - the cockroaches; They are very adaptable and whether you like them or not, they have a place in our lives.